JP5867758B2 - Optical pulse generator - Google Patents

Description

  The present invention relates to an optical pulse generator capable of generating and focusing chirp pulses and a corresponding method for generating and focusing such chirp pulses.

  Generating and focusing a chirp pulse is a commonly known application of lasers. Usually the chirp pulse passes through a stretcher, an amplifier and four diffraction gratings that allow the chirp pulse to be compressed in the time domain so that a pulse with a shorter duration is obtained compared to the original chirp pulse. After the compressed pulse exits the diffraction grating, it has a spatial and temporal alignment of its different color components. After the process of first stretching, then amplifying, and then compressing, the diameter of the pulse can become excessively large, so that each of the color components of the pulse is temporally and spatially aligned However, further focusing is required to achieve a high energy density on the target. The technique of stretching, amplifying, and compressing femtosecond pulses is known as “chirped pulse amplification” (CPA).

  The present invention relates to providing an optical pulse generator that can generate a chirped pulse and focus it on a specific target, the device being less prone to failure and sufficient time for the resulting component. And should have a simplified design that allows for spatial alignment.

  This problem is solved by the optical pulse generator according to claim 1 and the method for generating chirp pulses according to claim 9. The dependent claims contain preferred embodiments of the invention.

  The optical pulse generator includes a source for supplying a chirp pulse and a compressor for the chirp pulse, and the compressor can process the propagation direction of the chirp pulse depending on the wavelength. 1 and 2 and a focusing device having a predetermined focal point, the optical pulse generator comprising: a first processing device in which the second processing device is in the direction of chirp pulse propagation; And the first and second processing devices can process the direction of propagation of the chirped pulse so that the chirped pulse is converted to a pulse after passing through the second processing device, and the different colors of the pulse The components are characterized by being spatially spread and well aligned in time. In this context, being well aligned in time means that the refocusing of the spatially spread color components that may be necessary is that different color components, preferably all color components, reach the collection point at the same time. Means that it can be achieved using achromatic devices such as mirrors or good approximation lenses. By providing first and second processing devices that are capable of generating pulses containing different color components that are spatially spread out from the chirp pulse and are well aligned in time, the wavelength is varied with respect to the direction of propagation of the chirp pulse. Other devices that depend on it can be avoided.

  When different color components that are spatially spread and sufficiently aligned in time propagate in parallel to each other, the different color components propagate on a plane perpendicular to the propagation direction in the time domain.

  When different color components that are spatially spread and sufficiently aligned in time propagate to converge or diverge in the spatial domain, they are on the spherical surface whose center is the convergence point or the origin of the divergence propagation direction. To propagate.

  Thus, it is possible to focus spatially spreading components that are well aligned in time by optical focusing components without chromatic aberration (eg lenses, or concave mirrors), where different color components reach the focal point at the same time. . They preferably interfere constructively and produce high power in a very short time (eg, less than 50 fs).

  In one embodiment, the optical pulse generator comprises two (identical) diffraction gratings (as first and second processing devices) and a curved mirror (and / or lens), where the mirror and / or lens is: It is arranged after the diffraction grating in the propagation direction of the chirp pulse. By providing identical diffraction gratings (which means, for example, that the grating spacing of the diffraction gratings is the same), the optical pulse generator can be made with minimal effort with respect to the number of optical systems required. .

  In other embodiments, the optical pulse generator comprises two different diffraction gratings (as first and second processing devices) and a focusing lens (and / or focusing mirror), where the lens is in the direction of chirp pulse propagation. It is arranged in front of the diffraction grating. With this arrangement, propagating pulses from the second processing device, such as the second diffraction grating, require only a slight focusing. Alternatively, this can be achieved by using two diffraction gratings that are not parallel.

  In another embodiment, the optical pulse generator is characterized in that the first and second processing devices are prisms. By providing a prism, it is possible to obtain a runtime difference of further different color components, thereby achieving temporal alignment.

  In another embodiment, the optical pulse generator comprises a diffraction grating and a prism that are first or second processing devices. This configuration can combine the advantages of a diffraction grating and a prism.

  In other embodiments, the focusing device comprises at least a mirror or lens. By providing such a chromatic aberration-free focusing device, unintentional differences in different color components at run time are avoided and the achieved temporal alignment is maintained.

  In other embodiments, the light pulse generator can focus the different color components of the chirp pulse onto a given line (eg, using a cylindrical lens or mirror), where the line is essentially an average of the different color components. Is perpendicular to the propagation direction. Thus, spatially and temporally aligned components can be generated on the line, enabling a wide variety of applications.

  In another embodiment, the optical pulse generator is characterized in that the source comprises a laser oscillator, a pulse stretcher, and an amplification stage for supplying chirp pulses. By using such a known device, it is possible to rely on the already known device for the construction of the optical pulse generator.

  By using such an optical pulse generator, a method of generating a pulse can be realized, in which the chirped pulse passes through the first processing device before passing through the second processing device. , The direction of propagation of the chirp pulse is processed by the first and second processing devices such that the chirp pulse is converted to a pulse after passing through the second processing device, and the different color components of the pulse are spatially It is characterized by being sufficiently aligned in terms of spreading time. Thereby, the generated pulses can be used in many ways because they result in a high energy density and a complete pulse peak structure without leading peaks and / or unintentional dispersion.

  In one embodiment, the compressed and focused pulse has a duration at the focal point of less than 1 ns, preferably less than 1 ps, more preferably less than 50 fs. Such short pulses allow high energy application in a short time frame when generated and focused by the above method, thus providing the ability to process material structures.

  In another embodiment, the method is characterized in that the chirped pulse passes in the propagation direction through two identical processing devices (eg diffraction gratings) and a (focusing) mirror. By using two identical diffraction gratings, the apparatus and method can be simplified in a simple manner by replacing the diffraction grating with two other identical diffraction gratings when other frequencies are intended for the chirped pulse. Since it can be adapted to the new wavelength, the method can be applied flexibly.

  In another embodiment, the method is characterized in that the chirped pulse passes in the direction of propagation through a lens or focusing mirror and two different processing devices (eg diffraction gratings). By passing through the lens before passing through the first and second processing devices, for example in the form of a diffraction grating, at least prefocusing of the chirped pulse can occur, thereby making the further focusing device meaningless.

  In another embodiment of this method, the chirped pulse passes through two prisms in the propagation direction. Thereby, temporal alignment is achieved, at least in part, because different color components at different runtimes need to propagate through the prism.

  In another embodiment, the method is characterized in that the chirped pulse passes through a prism and a diffraction grating. Thus, temporal alignment can be achieved using the optical properties of the diffraction grating and prism.

  In another embodiment, the method is characterized in that the different color components are focused on a predetermined line, and the predetermined line is essentially perpendicular to the average propagation direction of the different color components. By bringing the pulses onto a given line, spatially extended energy application is possible, thus enabling a wide variety of applications.

  In an alternative embodiment, the second diffraction grating is replaced by a plane mirror so that the virtual image of the first diffraction grating provided by the plane mirror coincides, preferably exactly, with the position of the second diffraction grating. . This can also be achieved using prisms and mirrors as well.

It is the schematic of a chirp pulse application system. 1 is a schematic diagram of a chirped pulse compressor according to the present invention. FIG. 1 is a schematic diagram of a chirped pulse compressor according to the present invention. FIG. FIG. 2 is a diagram illustrating an implementation of a chirp component compressor according to a preferred embodiment of the present invention. FIG. 2 is a diagram illustrating an implementation of a chirp component compressor according to a preferred embodiment of the present invention. FIG. 2 is a diagram illustrating an implementation of a chirp component compressor according to a preferred embodiment of the present invention. FIG. 2 is a diagram illustrating an implementation of a chirp component compressor according to a preferred embodiment of the present invention.

FIG. 1 shows a chirped pulse generator 100 according to the present invention comprising an oscillator 105 that generates pulses. The oscillator can be, for example, a Ti: Sa laser that outputs femtosecond pulses. The pulses are preferably output at a high repetition rate of 10 ⁷ to 10 ⁹ Hz, more preferably about 10 ^{8 to} 5 × 10 ⁸ Hz, and the pulse energy is preferably in the range of 10 ⁻⁸ to 10 ⁻¹⁰ J, more preferably 10 ^{−9 to} 5 × 10 ⁻⁹ J. The duration of the pulse can vary between 20 fs and 1 ps. This pulse is directed to the stretcher 104, which stretches the pulse in time (10 ³ to 10 ⁵ times) to reduce the energy density. The stretched pulse is then directed to amplifier 102, which in combination with 106 pumping system 103 that pumps amplifier 102 amplifies the stretched pulse. The amplification factor can be in the range of 10 ⁴ to 10 ⁶ times. The amplified stretched pulse is then directed to a compressor 110 that compresses the stretched pulse. In order to obtain the required energy density and power, for example in the case of laser-induced proton emission on a thin foil, the peak power of the output pulse must be in the range of 1-100 TW. Depending on the exact magnitude of power required, the required amplification factor, repetition rate, and pulse energy can be calculated taking into account the breakdown thresholds of the device components.

  The compressor according to the invention will achieve a sufficient temporal alignment of the frequency components (color components) in the resulting pulse 107. On the other hand, the compressor 110 provides a spatial alignment of all frequency components at a given point 108 to achieve high energy application at the given point 108, as described below. According to the present invention, the compressor 110 (also referred to as a chirp compressor 110) includes first and second processing devices that can process the propagation direction of the chirp pulse depending on the wavelength. The processed chirp pulse is converted to a pulse as it passes through the first and second processing devices. The pulse will contain different color components after passing through the first and second processing devices, and these components will spread spatially. Thus, a focusing device is used to focus the spatially spreading components so that they are spatially aligned at a given collection point. Note that the present invention includes the compressor 110, and the oscillator 105, expander 104, amplifier 102, and pumping system 103 may be derived from or identical to devices generally known from CPA. Should.

  The focal point 108 can be provided with a target that is amplified, compressed, and impinged by the focused pulse. The optical field between the chirp compressor 110 and the focal region is a focused optical field (a converging optical field), but different color components (i.e. light with different wavelengths) are spatially spread. . For example, in FIG. 1, the high frequency component of the light pulse may be present only on the right side of the optical field and the low frequency component of the pulse may be present only on the left side. In the focal region 108, the different color components of the pulses overlap and interfere with each other in an intensifying manner, producing a high power pulse with a duration of less than 50 fs, for example.

  FIG. 2A shows a more detailed view of the chirped pulse compressor 210. As can be seen, the chirped pulse compressor 210 comprises a first processing device 211 and a second processing device 212 shown as an optical diffraction grating. As described below, other implementations (eg, prisms) of the first and second processing devices are possible.

  Referring to FIG. 2A, in any case, the first and second processing devices 211 and 212 may cause the incoming chirp pulse 220 to have spatially independent or spread color components 221 and 222 (the color components are frequency components). It should be noted that the incoming chirped pulse 220 is affected by diffraction so that it is converted into a gathered pulse (also referred to as “collected”). It should be noted that the classification shown in the two frequency components 221 and 222 is for simplicity only. In practice, each frequency component contained in the chirp pulse 220 is guided through the first and second processing devices 211 and 212 and then spatially independent of the path taken by the other frequency component of the chirp pulse 220. It propagates along the route. In addition, the first and second processing devices 211 and 212 exit the chirp pulse compressor 210 if no other focusing device is used before or after the first and second processing devices 211 and 212. In addition, the different color components 221 and 222 have optical properties such as propagation parallel to each other (eg grating constant (or line density) if using a diffraction grating, or refractive index in some other implementations). It should be noted. Different color components are well aligned in time and travel on a plane perpendicular to the direction of propagation.

To explain the above in more detail, reference is made to FIG. 2B. Here, two frequency components (also called color components) are considered. These components result from the chirp pulse 220 shown in FIG. 2A. Therefore, the frequency component 221 corresponds to a frequency different from the frequency component 222. As can be seen from FIG. 2B, these components are spatially independent and have a spatial and temporal distance from each other along their propagation direction. Starting with the frequency component 221 at position B and time t _0, the frequency component 221 propagates along the path indicated by the arrow and enters the first processing device 211 at the point of incidence C. The frequency component 221 is incident on this point C at time t ₁ . The processing dependent on the wavelength of the propagation direction of the frequency component 221 which is achieved by the first processing device 211, the frequency component 221 propagates along the broken line, incident on the second processing device at point E at time t ₂ It will be. Again, the frequency component 221 propagates along the broken line so as to pass the point G at time t ₃ by processing dependent on the wavelength in the propagation direction.

Another frequency component 222 corresponding to a frequency different from the frequency of the first component 221 starts at point A instead of point B at the same time t ₀ due to the temporal expansion of the chirp pulse described above. The frequency component 222 reaches point C at time t ₁ + Δ, where Δ is the time required for the second frequency component 222 to pass the distance between point A and point B. Due to the different frequencies, the component 222 arrives at the second processing device 212 at point D after passing through the first processing device 211 at time t ₄ . By undergoing the process of different propagation directions from the first component 221, the second component 222 after passing through the second processing device 212, and reaches the point F at time t _5. Thus, to achieve sufficient temporal alignment of the frequency components 221 ′ and 222 ′ exiting the chirped pulse compressor 210, the different starting points of the first frequency component 221 and the second frequency component 222 at point C. The time difference resulting from the different incident times due to A and B must be compensated. Accordingly, the first processing device 211 and the second processing device 212 have a propagation time from the point C to the point G over the point E to the point G with respect to the first frequency component 221. It is constructed and designed to be equal to the value obtained by adding the initial time difference Δ to the propagation time exceeding D to the point F. This and the parallel alignment of the spatially spread components 221 ′ and 222 ′ configure the first and second processing devices 211 and 212 at specific angles and have specific diffractive or refractive properties depending on the wavelength. (E.g., lattice constant, or refractive index). Thereby, the parallel and spatially spread frequency components 221 'and 222' are temporally aligned and thus simultaneously impinge on a given surface perpendicular to the propagation direction, i.e. Each will pass simultaneously. This is achieved by using various focusing devices that can be placed before the chirped pulse passes through the first and second processing devices 211 or 212 or after the pulse leaves them. The focusing device focuses the components 221 and 222 to a predetermined point and is achromatic, i.e., provides focusing of the components regardless of their wavelength.

が、すでに得られた空間的整列により周波数に無関係である知られているＣＰＡとは異なり、本発明のベクトル

は依然としてそれぞれの周波数成分の周波数に依存することに注目すべきである。これは本発明の場合は、電界成分は

に対応することを意味し、但しωはいずれかの周波数成分（２２１’又は２２２’のような）の周波数であり、ｋ（ω）は周波数に依存する波数である。従って第２の処理デバイスを出た結果としてのパルスは、波長に依存しない伝搬方向によって特徴付けられる従来型のレーザビームには対応しない。その代わりにこれは、それぞれが所与の伝搬方向

において移動する１組の波動である。従って時間的に十分に整列した成分は所与の時間において異なる方向に沿って伝搬するが、それらは時間的に十分に整列しているので、少なくとも１つの所定の集光点において空間的整列を達成するために、ミラー又はレンズなどの無彩色のデバイスを用いることができる。 Resulting pulse propagation direction, ie unit propagation vector

Unlike known CPA, which is independent of frequency due to the spatial alignment already obtained,

Note that is still dependent on the frequency of each frequency component. In the case of the present invention, the electric field component is

Where ω is the frequency of any frequency component (such as 221 ′ or 222 ′) and k (ω) is the frequency dependent wavenumber. Thus, the resulting pulse leaving the second processing device does not correspond to a conventional laser beam characterized by a wavelength independent propagation direction. Instead, this is each a given direction of propagation

Is a set of waves that move at. Thus, components that are well aligned in time will propagate along different directions at a given time, but they are well aligned in time so that spatial alignment at at least one predetermined collection point is achieved. To achieve this, achromatic devices such as mirrors or lenses can be used.

  Unlike conventional CPA pulse compression, where four diffraction gratings are used, or each of the two diffraction gratings is passed twice by means of a mirror, where only the two diffraction gratings have passed, the different color components are already in time. Well aligned. In conventional CPA compression, the temporal compensation is only halved just by passing through two diffraction gratings. The other half of the temporal alignment is made by the third and fourth passes of the diffraction grating. In conventional CPA, sufficient temporal compensation is achieved only after four passes through the diffraction grating. Conventional CPA also achieves spatial alignment after four passes through the diffraction grating.

  3A-3D show several implementations of the first and second processing devices and the focusing device. It should be noted that the implementations shown can be combined or used interchangeably to achieve the intended result, or used in addition to each other.

  FIG. 3A shows first and second processing devices 311 and 312 that are diffraction gratings as described in FIG. 2, and lens 313 is a chirped pulse, or propagation direction of frequency components 321 and 322 representing it. In the front of the diffraction grating. Diffraction gratings typically have a grating constant of thousands of lines per millimeter. The grating constant to be used, and hence the type of diffraction grating, depends strongly on the frequency range of the incident chirp pulse. Lens 313 has a focal point at point 308. Due to the diffraction of the frequency components 321 and 322 as they pass through the first and second processing devices, the different color components converge towards the focal point 308 and spread spatially but are well aligned in time. As a result of this, every frequency is focused at point 308, thereby preferably providing as much energy as possible for a short time.

  FIG. 3B shows a corresponding configuration in which a lens 330 is disposed in the propagation direction of the first and second frequency components 321 and 322 after the first and second processing devices 311 and 312. As described above, the first and second processing devices 311 and 312 convert the incoming chirp pulse 320 into parallel frequency components 321 ′ and 322 ′ that are well aligned in time but spread spatially. be able to. The same result as described in FIG. 3A is achieved, ie the various frequency components 321 ′ and 322 ′ are focused on the point 308 where they reach simultaneously after passing through the lens 330.

  FIG. 3C shows a corresponding configuration in which the parabolic mirror 314 is used to focus the different frequency components 321 'and 322'. Like a lens, the parabolic mirror 314 collects both so that the time-aligned frequency components 321 ′ and 322 ′ propagate along the optical path having the same length when passing through the parabolic mirror 314. The frequency components 321 ′ and 322 ′ that are sufficiently aligned in time so as to be simultaneously incident on the light spot 308 but spatially spread in parallel are redirected.

  FIG. 3D shows an alternative implementation of the first and second processing devices 311 and 312. Here, the first and second processing devices 311 and 312 cause the incident chirp pulse 320 to induce a boundary surface of the first prism 311, and thus the first boundary surface and the second boundary surface of the first prism 311. It is made of a prism having a pre-defined refractive index and configured at a predetermined angle so as to be refracted on a surface. Thereby, the incident chirp pulse 320 is subdivided into various frequency components, for example, a first frequency component 321 and a second frequency component 322 that propagate along different optical paths. Accordingly, these components arrive at the second prism 312 at different points of the interface at different angles at different times. Depending on the refractive index of the second prism 312 and its geometric dimensions, the frequency components 321 ′ and 322 ′ pass through the second prism 312 in time, but spatially spread, preferably as parallel color components. Will do. A focusing device (such as a lens or mirror) can then be applied to focus the different color components to a predetermined focal point.

  The disclosed implementations of a chirped pulse compressor can be combined, i.e., provided with a lens before the first and second processing devices or after the first and second processing devices, and under actual conditions the first Since the first and second processing devices do not provide the described results to the desired accuracy, further providing a parabolic mirror or the like to achieve the necessary correction of the optical path of the different color components of the pulse It should be noted that is possible.

  In order to realize the first and second processing devices 311 and 312, it may be advantageous to use one diffraction grating and one prism rather than two diffraction gratings or two prisms. Considering this, if diffraction gratings are used, to implement the first and second processing devices 311 and 312 such that the intended result is achieved by their mutual relationship and their specific characteristics. Has three degrees of freedom. The first and second degrees of freedom are the lattice constants of each diffraction grating. The third degree of freedom is the angle at which these diffraction gratings are aligned with each other. Therefore, in order to obtain the above-mentioned result, the angle at which two diffraction gratings having the same grating constant should be aligned differs from the angle at which two diffraction gratings having different grating constants should be aligned. The same is true when using two prisms, or one prism and one diffraction grating. In the case of two prisms, the refractive index and the interface angle represent the corresponding degrees of freedom. Therefore, when two prisms 311 and 312 are used according to FIG. 3D, a further degree of freedom is obtained. The first degree of freedom is their mutual alignment, the second and third degrees of freedom are their respective refractive indices, and the fourth and fifth degrees of freedom are surrounded by the refractive interface of each prism. Is an angle.

  It should be noted that the above arrangement can focus the different color components of the pulse resulting from the chirp pulse to a given focal point by first achieving temporal alignment of the different color components. This makes it possible to achieve spatial alignment by using only wavelength independent devices such as lenses or mirrors.

The target can be configured to generate protons when a pulse strikes the target. The target can be a thin foil, such as a thin metal foil, so that the pulse causes accelerated proton release that can be used for medical purposes such as the production of radiopharmaceuticals. In the focal region, power densities up to 10 ¹⁴ to 10 ¹⁶ or 10 ¹⁸ W / cm ² and even higher power densities are possible.

One particular example of the above-described embodiment is a set of two diffraction gratings arranged parallel to each other, at a distance of 6-10 cm to each other, preferably 8-9 cm to each other, in particular 8.6 cm to each other. This distance is related to the vertical distance between the parallel diffraction gratings. The two diffraction gratings have 1000 to 2000 lines / mm, preferably 1300 to 1800 lines / mm, in particular 1740 lines / mm, and are large enough so that the diffracted pulses are covered by each diffraction grating. Therefore, the required size of the diffraction grating depends on the diameter of the incident pulse and can vary from implementation to implementation. Laser pulses having a wavelength of 600 to 1000 nm, preferably 700 to 900 nm, particularly 800 nm, and a Fourier limit band of 20 to 40 fs, preferably 25 to 35 fs, particularly 30 fs can be used. This laser pulse is stretched to about 20-60 ps, preferably 30-50 ps, in particular 41 ps, and then a predefined angle with respect to the normal of the first diffraction grating, preferably 30-70 °, most preferably 50 It hits the first of the two gratings at -60 °, in particular 53 °. At a similar angle, the second diffraction grating forms a set of parallel rays emanating from the second diffraction grating, all of which move parallel to one another but spread in space, i.e. in the distance from one another. . The preferred compression mechanism in this case advantageously induces a delay dispersion of 400,000 to 50000 fs ² , more preferably 430000 to 460000 fs ² , in particular 452030 fs ² .

DESCRIPTION OF SYMBOLS 100 ... Chirp pulse generator 102 ... Amplifier 103 ... Pumping system 104 ... Stretcher 105 ... Oscillator 107 ... Pulse 108 ... Predetermined point, condensing point, focal area 110 ... Compressor, chirp compressor 210 ... Chirp pulse compressor 211 ... first processing device 212 ... second processing device 220 ... chirp pulse 221 ... color component, frequency component 221 '... frequency component 222 ... color component, frequency component 222' ... frequency component 308 ... focusing point 311 ... first Processing device 312 ... Second processing device 313 ... Lens 314 ... Parabolic mirror 320 ... Chirp pulse 321 ... Frequency component 321 '... Frequency component 322 ... Frequency component 322' ... Frequency component 330 ... Lens

Claims (12)

A supply source for supplying a chirp pulse , comprising: a laser oscillator (105); a pulse stretcher (104); and an amplification stage (102) for supplying the chirp pulse; compressor for compressing (110) and an optical pulse generator comprising the compressor, the first processing device the propagation direction of the chirped pulses can be processed depending on the wavelength (311) And an optical pulse generator (100) comprising: a second processing device (312); and a focusing device comprising a lens (313) having a predetermined focal point (308) .
The first processing device and the second processing device are disposed after the amplification stage in the propagation direction of the chirp pulse;
The second processing device is disposed after the first processing device in a direction of propagation of the chirp pulse;
The first processing device and the second processing device are diffraction gratings;
The first processing device and the second processing device can process a propagation direction of the chirp pulse so that the chirp pulse is converted into a pulse after passing through the second processing device;
Different color components of said pulses are temporally Alignment spread spatially,
The lens (313) is disposed in front of the first processing device and the second processing device in the direction of propagation of the chirp pulse, and the condensing point (308) of the lens is the propagation of the chirp pulse. An optical pulse generator, characterized in that it is after the first processing device and the second processing device in the direction . The first processing device and the second processing device are the same diffraction grating, and the focusing device further includes a mirror (314), or the focusing device replaces the lens (313) with a mirror (314). ) wherein the mirror (314), characterized in that arranged in the propagation direction of the chirped pulse after the first processing device and the second processing device, the optical pulses according to claim 1 Generator. Characterized in that said first processing device and the second processing device are two different diffraction grating, the optical pulse generator of claim 1. The focusing device further comprises at least a mirror (314) , wherein the mirror (314) is disposed after the first processing device and the second processing device in the direction of propagation of the chirp pulse. The optical pulse generator according to claim 1 or 3 . The spatially spreading component of the chirped pulse can be focused on a predetermined line, the line being essentially perpendicular to the average propagation direction of the different color components. The optical pulse generator as described in any one of 1-4 . A supply source for supplying a chirp pulse , comprising: a laser oscillator (105); a pulse stretcher (104); and an amplification stage (102) for supplying the chirp pulse; A method of generating pulses by using an optical pulse generator (100) comprising a compressor (110) for compressing, wherein the compressor processes the propagation direction of the chirped pulse depending on the wavelength In a method, comprising: a first processing device (311) and a second processing device (312) that can and a focusing device comprising a lens (313) having a predetermined focal point (308) .
The chirp pulse passes through the lens after leaving the amplification stage (102), and the lens converges after the first processing device and the second processing device in the direction of propagation of the chirp pulse. Has a point (308),
The chirp pulse passes through the first processing device after passing through the lens and before passing through the second processing device;
The direction of propagation of the chirped pulse is processed by the first processing device and the second processing device such that the chirped pulse is converted to a pulse after passing through the second processing device;
The pulses of different color components, characterized in that it is temporally Alignment spread spatially methods. The method according to claim 6 , characterized in that the compressed focused pulse has a duration of less than 1 ns, preferably less than 1 ps, more preferably less than 50 fs. The first processing device and the second processing device are the same diffraction grating, and the focusing device further includes a mirror (314), or the focusing device replaces the lens (313) with a mirror (314). ) comprises a, in the chirped pulse propagation direction, and the first processing device and the second processing device, characterized in that it passes through said mirror (314), according to claim 6 or 7 Method. The first processing device and the second processing device are two different diffraction grating, passes in the chirped pulse propagation direction, and said lens, and said first processing device and the second processing device The method according to claim 6 or 7 , characterized in that: The first processing device and the second processing device are prisms, and the chirp pulse passes through the first processing device and the second processing device in a propagation direction. The method according to 6 or 7 . One of the first processing device and the second processing device is a prism, and the chirped pulse passes through the one of the first processing device and the second processing device. Item 8. The method according to Item 6 or 7 . The different color components is focused on a predetermined line, said the predetermined line is essentially characterized in that the the average propagation direction and vertical in the different color components, any one of the claims 6-11 The method according to item.

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